In the Greek mythological story of the Trojan War, Agamemnon, the king of Mycenae and the leader of the Greek forces, refused to give back to Apollo's priest his daughter, named Iphigenia.
According to the myth, Agamemnon had angered the god Apollo, who sent a plague upon the Greek army as punishment. To appease Apollo and lift the plague, the seer Calchas revealed that Agamemnon had to sacrifice his daughter, Iphigenia, to the gods. Agamemnon reluctantly agreed to the sacrifice, tricking Iphigenia into coming to Aulis under the pretense of marrying her off to the hero Achilles.
In some versions of the myth, it is said that at the last moment, when Agamemnon was about to sacrifice Iphigenia, the goddess Artemis intervened and substituted a deer for the girl. Iphigenia was then whisked away to Tauris (modern-day Crimea) by Artemis and served as her priestess.
Agamemnon's refusal to give back Iphigenia to Apollo's priest was a significant act that had far-reaching consequences and played a part in the tragic events that unfolded during the Trojan War and the subsequent events in Greek mythology.